This invention relates to new and improved mortar compositions, which are especially suitable in grouting applications and filling the joints between ceramic tiles. This invention relates to the compositions, the method of grouting using said compositions and the installed product wherein said compositions are used to bond the individual tiles. More particularly, this is concerned with aqueous non-hydraulic grout and thin-bed mortar compositions which comprise a film-forming, water-dispersible cross-linkable polymer and a water-insoluble filler and to the method of grouting and bonding ceramic tile, cement tile, bricks, natural stones, mineral chips, glass tessera and glass plates, employing said compositions.
Conventional mortars for setting tile consist of Portland cement, lime and sand. Water is added to this mixture to obtain workability and to take part in the hardening or curing action by means of which the cement forms a gel. These mortars are not entirely self-curing in that they tend to lose considerable water by evaporation into the surrounding atmosphere and also by absorption into the tile or masonry which is being set. If the water loss is too great, the curing action is incomplete and the mortar becomes soft and chalky. Moreover, these conventional mortars require heavy, thick and generally multiple layers to be placed before setting the tile. This entails the use of large quantities of these materials and considerable labor for mixing, placing and trowelling of such underlayers. In addition, very wet conditions must be maintained for proper hardening and bonding which leads to the troublesome operation of soaking all nonvitreous ceramic tile before setting and the taking of considerable precautions to insure the regulation of such wet conditions during the period of curing. Another disadvantage of such mortars concerns the impracticality of using them over such substrates as gypsum wallboard or plaster.
A more recent innovation in the tile setting industry relates to the use of dry set mortar and grouts. However, these compositions generally stain badly, crack easily and develop poor strength under dry conditions. Furthermore, these materials have poor acid and chemical resistance.
The compositions described in the instant application are essentially free of the undesirable properties which are characteristic of the aforementioned mortar compositions. More specifically, they have easy to trowel non-Newtonian consistencies; they are suitable grouts for filling joints between impervious and absorptive types of ceramic tile; they are suitable for use as thinset mortars; they exhibit minimal shrinkage and they become highly water and stain resistant after a period of time.